The ABB S803S-K10 is a 3-pole miniature circuit breaker from the S800S series, rated at 10 A with Trip Curve K characteristics. It mounts on a standard DIN rail and handles 230 VAC circuits, with a 50 kA interrupting rating that gives real fault-clearing headroom in industrial panels — that's well above the typical 6–10 kA you see on residential-grade breakers, so it's sized for plant-floor distribution where fault currents run higher.
Trip Curve K means it's designed for inductive loads — motors, transformers, solenoid valves — where the inrush current is higher than a resistive load but not as sharp as a lighting or drive startup. The magnetic trip threshold on a K-curve typically sits between 8x and 12x the rated current, so it holds through a motor start without nuisance tripping but still clears a hard fault fast. The 50 kA interrupting capacity at 230 VAC means this breaker can safely interrupt a short-circuit fault up to 50,000 A without welding its contacts or venting ionized gas into the panel — that's the kind of rating you spec for a main distribution board or a sub-feed where the available fault current is known to be high.